Fermentation process



Patented Dec. lg, 1928.

UNITED STATES PATENT OFFICE.

EIIIIIOTTI ROSS WEEK, WASHINGTON, PENNSYLVANIA.

I ERMENTATION PROCESS.

I No Drawing.

My invention relates to improvements in the fermentation of carbohydrate mashes; particularly in the sterilization of such mashes and the preservation of the purity of culture during the fermentation process. My

invention is of special value and application in connection with fermentation processes for the manufacture of butyl alcohol and acetone.v Improvement in yield of the desired products and expedition of the manufactur-- ing operation are among the important advantages of my invention. The production of butyl alcohol and acetone, for example, through the fermentation of various carbohydrate materials is dependent upon the ferdesired products may be decreased, or in extreme cases there may be no yield, through the activities of certain undesirable organisms. which are commonly associated with cereal grains and often found in the soil and in the air, arerapid growers and are resistant to heat.

Hitherto it has been common practice to cook, for extended periods, all mash for use,

- to use the same example, in the production of butyl alcohol and acetone. The cooking is intended to gelatinize the starch which is present and to rid the mash of all bacteria before it is inoculated with a pure culture of the organism used to produce the butyl alcohol and acetone. Only a short period of cooking is necessary completely to gelatinize starchv present in the mash. On the other hand, the cooking necessary to kill off all foreign organisms present is long and retards the manufacturing pperation. Again, in the processes hitherto used, it has been found difficult if not impossible to preserve the sterility of the prepared mash and to preserve the purity-of culture after inoculation. In order to guard against such difliculties, it has been common practice to have all parts of the equipment used in the manufacturing operation fitted with facilities for sterilizationby live steam and to provide, at all points where danger from contamination is present, for example, at'valves and bushings, glands impregnated with strong antiseptic solutions. In spite of such precautions, contamination experienced.

Such contaminating organisms,

stance highly toxic with respect to most Application filed March 4, 1927. Serial No.'172,934.

I have discovered that sterilization can be promoted and contamination avoided or.

minimized by subjecting the mash to treatment with bacteriocidal and bacteriostatic substances exerting a selective action, permit ting activity of selected cultures, but inhibiting activity of any contaminants, and, ac-

cording to my invention, I treat the mash to be subjected to the fermentatidn process with such an antiseptic substance, non-toxic with respect to the selected culture, but toxic with respect to contaminating organisms.

I have discovered, again to refer-to the same example, that bacteriocidal and, bacteriostatic substances such as butyl resorcinol and butyl phenol, and their homologues and similar compounds, exert a selective bacteriocidal and bacteriostatic action which makes their use particularly advantageous in the treatment of carbohydrate mashes in the manufacture by fermentation processes of butyl alcohol and acetone.

Butyl resorcinol, for example, is a subbacteria, exerting a' bacteriostatic action in dilutions of 1:50,000 or even greater dilutions, but. this substance, in such concentrations,'or even in greater concentrations, has little, if any, effect upon the bacteria active in the production of butyl alcohol and acetone. p

The normally high toxicity of butyl resorcinol and butyl phenol; or example, is partly due to the butyl radical, and it may be that the relative non-toxicity of such butyl deriva tives with respect to cultures active in the fermentation of carbohydrate mashes to produce butyl alcohol is due, in this instance, to the fact that these substances contain as their principal toxic component a radical common to a product of the fermentation resulting from the activity of these bacteria.

As an example of one application of my innecessary for erably shortened. v Likewise, after sterilizative in this fermentation but toxic With retion, the mash is resistant to contamination spect to contaminating organisms.

due to the antiseptic which it contains. The 2. An improvement in the fermentation of mash may then be used either for the prepacarbohydrate mashes with selected cultures ration of seed culture, stock culture, or for for the production of butyl alcohol and ace- -the fermentation in the manufacturing opertone which comprises treating the mash with ation in the usual way. an antiseptic non-toxic with respect to cul- The antiseptic substance may be added to tures active in this fermentation but toxic the mash either before or during sterilizawith respect to contaminating organisms and tion in either case it exerts its action during sterilizing the treated mash. and subsequent to sterilization. Addition of 3. An improvement in the fermentation of the antiseptic after sterilization or after parcarbohydrate mashes with selected cultures tial sterilization is also useful in connect-ion for the production of butyl alcohol and acewith such fermentation processes. Added tone which comprises treating the mash durafter sterilization or after partial sterilizaing sterilization with an antiseptic non-toxic tion, the antiseptic acts as a preservative of ,with respect to cultures active in this fermenpure culture during fermentation and retation but toxic with respect to contaminatduces to a minimum the activity of any uning organisms.

desirable contaminants. I have also found 4. An improvement in the fermentation of that in the presence ofsubstzinces exerting carbohydrate mashes with selected cultures such selective bacteriostatic action, for examfor the production of butyl alcohol and aceple, butyl resorcinol in fermentation to protone which comprises treating the mash with duce butyl alcohol and acetone absolute pun an antiseptic non-toxic with respect to culity of culture is not essential and that organtures active in this fermentation but toxic tone, which comprises sterilizing the mash tion process.

isms which otherwise might act as contamiwith respect to contaminating organisms. nants can, to some extent, be present without 5. An improvement in the fermentation of detriment to the operation of the fermenta carbohydrate mashes with selected cultures for the production of butyl alcohol and ace- I claim: I 7 tone which comprises treating the mash with 1. An improvement in the fermentation of a bacteriocidal and bacteriostatic substance carbohydrate mashes with selected cultures containing as a major toxic component a for the production of butyl alcohol and acebutyl phenol.

In testimony whereof I aflix my signature. and treating the sterilized mash with an antia a septic non-toxic with respect to cultures ac- ELLIOTT ROSS WEYER. 

